Unsafe toxin at Rufus Woods Lake closes in-water recreation

By NCBI
Aug 12, 2011

An unsafe level of algae toxin has been discovered at Rufus Woods Lake, prompting the U.S. Army Corps of Engineers to post Washington State Department of Health warnings against swimming, water skiing and other in-water activities at the lake.

While it's safe to eat properly cleaned and gutted fish, the water should not be consumed and steps should be taken to keep livestock and pets away from the water. Boaters are advised to avoid areas where algae blooms are present.

The toxin of concern is anatoxin-a, a naturally occurring nerve toxin produced by some blue-green algae blooms, which has been shown to be lethal to animals if ingested at high enough concentrations.

Samples from the lake were taken and forwarded to King County Environmental Laboratories for testing and analysis. Two separate sample test results showed that the lake contained 6-31 micrograms of anatoxin-a, a powerful and
quick-acting toxin, per liter of water.

The Washington Department of Ecology and Washington Department of Health have notified the Corps that the analyzed samples are in excess of the state recommendation of one microgram per liter for recreational uses of the water. Samples will continue to be taken and analyzed weekly until anatoxin-a levels are determined to be below state recreational guidance values.

Access to Rufus Woods Lake remains open to the public.

For more information about toxic blooms, see the Department of Ecology algae website http://www.ecy.wa.gov/programs/wq/plants/algae/index.html and the Department of Health website http://www.doh.wa.gov/ehp/algae/default.htm